[WinEH] Fix the wrong alignment orientation during calculating EH frame.

Summary: This is a bug fix for further issues in PR43585.

Reviewers: rnk, RKSimon, craig.topper, andrew.w.kaylor

Subscribers: hiraditya, llvm-commits, annita.zhang

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70224